Convert CSV to JSON and JSON to CSV

Transform your data between CSV and JSON formats seamlessly. Customize delimiters, headers, and formatting for perfect conversion.

Convert CSV to JSON and JSON to CSV

Transform your data between CSV and JSON formats seamlessly with custom delimiters.

CSV Input

Delimiter:

JSON Output

Output will appear here

How the CSV to JSON Converter Works

Paste your CSV data or select JSON to CSV mode. The converter automatically detects the first row as headers and creates object keys from them. Each subsequent row becomes a JSON object.

Choose your delimiter: comma, tab, or semicolon. The parser handles quoted fields correctly, preserving commas inside quoted values. Type inference converts numbers and booleans automatically.

Output is ready to copy or download. JSON is pretty-printed for readability. CSV output properly escapes special characters. All conversion happens locally in your browser.

When You'd Actually Use This

Importing spreadsheet data

Export from Excel as CSV, convert to JSON for your web app. No manual reformatting needed. Perfect for bulk data imports.

API data transformation

Your API expects JSON but you have CSV data. Convert instantly without writing transformation code. Speeds up development significantly.

Creating test fixtures

Generate test data in a spreadsheet, export as CSV, convert to JSON fixtures. Much faster than hand-writing test data objects.

Exporting database results

Query results come as CSV. Convert to JSON for frontend consumption. Share data with team members in their preferred format.

Migrating between systems

Old system exports CSV, new system needs JSON. Use this as a quick migration tool. No custom scripts required for one-time conversions.

Learning data formats

See how CSV rows map to JSON objects. Understand the relationship between these common data formats. Great for students and new developers.

What to Know Before Using

First row is always headers.The converter treats the first line as column names. If your CSV has no headers, add a dummy first row. Headers become JSON keys.

Type inference is automatic."123" becomes number 123. "true" becomes boolean true. Empty cells become empty strings. This may not match your expectations.

Quoted fields handle special chars.Commas inside quotes are preserved. Newlines in quoted fields work correctly. The parser follows RFC 4180 CSV standards.

Nested structures aren't supported.CSV is flat. You can't represent nested JSON objects directly. Each CSV row becomes a flat JSON object.

Pro tip: For complex data with nested structures, consider using a dedicated ETL tool or writing custom transformation code. This converter excels at flat tabular data.

Common Questions

Can it handle large files?

Browser memory limits apply. Files up to a few thousand rows work well. For larger datasets, use command-line tools or server-side processing.

What encoding does it support?

UTF-8 is standard. Most modern CSV files work fine. Files with special characters from other encodings may need conversion first.

Does it preserve data types?

Numbers and booleans are inferred. Dates remain as strings. Complex types become strings. JSON doesn't have a native date type.

Can I customize the output format?

JSON is pretty-printed by default. For minified output, use a JSON minifier after conversion. CSV delimiter is customizable.

What about empty rows?

Empty rows are skipped. Rows with fewer columns get empty strings for missing values. Extra columns are ignored if headers don't match.

Is the conversion reversible?

Mostly. JSON to CSV loses type information - everything becomes strings. Structure is preserved but exact types may differ on round-trip.

Can I convert Excel files directly?

Export Excel as CSV first, then use this tool. Direct .xlsx support would require additional libraries. CSV is the universal interchange format.

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Convert CSV to JSON and JSON to CSV